This site is targeted at medical and radiology professionals, contains user contributed content, and material that may be confusing to a lay audience. Use of this site implies acceptance of our Terms of Use.

Guillain–Barré syndrome

Guillain–Barré syndrome (GBS) is defined as heterogeneous group of autoimmune polyradiculopathy, involving sensory, motor and autonomic nerves and is the most common cause of rapidly progressive flaccid paralysis 2


Most cases preceded by upper respiratory tract infections or diarrhoea 1-3 weeks before its onset, most commonly caused by Campylobacter jejuni (25-40% seropositive) 1,3. Molecular mimicry with the bacterial agents is thought to cause the autoimmunity. 

Other predisposing factors include recent surgery, lymphoma and systemic lupus erythematosus (SLE) 2

Clinical presentation

Classical presentation of GBS includes symmetrical ascending muscle paresis or palsy, areflexia or hyporeflexia along with variable degree of sensory or autonomic involvement.

Several sub-types have been described including:

Guillain–Barré syndrome is diagnosed by combination of clinical presentation,CSF study and electrophysiological criteria. 

CSF abnormalities are characterized by increase protein without pleocytosis, which is a non-specific finding, seen in many of the conditions which mimic GBS on imaging and clinically 1-2

Nerve conduction abnormalities include slow or blocked nerve conduction, prolongation of distal latency and f-waves. 

Chronic inflammatory demyelinating polyneuropathy (CIPD) is considered the chronic counterpart to GBS. 

Radiographic features

Radiologic studies are ordered to exclude other causes and in cases where nerve conduction studies and CSF examination are equivocal. MRI of the spine is most useful helps excluding other aetiologies such as transverse myelitis and compressive causes of polyradiculopathy. 


It is essential that contrast be administered if the diagnosis is suspected as non-contrast sequences are essentially normal 2

Typical findings in Guillain–Barré syndrome are nerve root thickening and enhancement surrounding the conus and extending along the cauda equina, resulting from break down in the blood brain barrier, which usually prevents enhancement 2.

The most common site of enhancement in Guillain–Barré syndrome is considered to be anterior nerve roots, although enhancement of the posterior nerve roots is also seen 2

In the brain the facial nerve is the most commonly affected 1.

Treatment and prognosis

Guillain–Barré syndrome is primarily managed with IV immunoglobulins or plasmapharesis along with supportive measures, which can speed up recovery 1

Typically improvement occurs after a number of weeks to months 1

Differential diagnosis

The differential is essentially that of nerve root / cauda equina enhancement: 

Related articles

Updating… Please wait.


Error Unable to process the form. Check for errors and try again.

Alert_accept Thank you for updating your details.